Question

There are plenty of examples of converting a wmf into a bitmap like: Reliable .wmf/wmf to Pixel based image conversion

但我需要扭转行动。我看不到病媒。我只想把照片放在一只手纸上,而不必对手法和手法作两手。我需要找到解决办法。最好见C#。

我首先认为,这项工作将:

using (Image img = Image.FromFile (path)) {
    img.Save (myStream, System.Drawing.Imaging.ImageFormat.Wmf);
}

但是,这在一段时间里抱怨说, en子是无效的。在什么地方,我能否建立这样的机构? 我不需要一个复杂的问题,而只是把形象描绘成一个 w。是否对最惠国中的支持形式有一些要求? I suppose png and bmp得到了支持,但也得到了支持。

Answer 1

http://msdn.microsoft.com/en-us/library/system.drawing.imaging.metafile.aspx”rel=“noreferer”>here:

When you use the Save method to save a graphic image as a Windows Metafile Format (WMF) or Enhanced Metafile Format (EMF) file, the resulting file is saved as a Portable Network Graphics (PNG) file instead. This behavior occurs because the GDI+ component of the .NET Framework does not have an encoder that you can use to save files as .wmf or .emf files.

但是,我猜想你已经走了这么远:

Here 某人正在一个文件Stream上绘制一份比图。

metafileStream = MakeMetafileStream(gdiBitmap);

与马克·马塔索姆(MakMetafileStream)合著:

private static MemoryStream MakeMetafileStream(Bitmap image)
{
  Graphics graphics = null;
  Metafile metafile= null;
  var stream = new MemoryStream();
  try
  {
    using (graphics = Graphics.FromImage(image))
    {
      var hdc = graphics.GetHdc();
      metafile= new Metafile(stream, hdc);
      graphics.ReleaseHdc(hdc);
    }
    using (graphics = Graphics.FromImage(metafile))
    { graphics.DrawImage(image, 0, 0); }
  }
  finally
  {
    if (graphics != null)
    { graphics.Dispose(); }
    if (metafile!= null)
    { metafile.Dispose(); }
  }
  return stream;
}

Interesting stuff. But as to the encoder thing...

http://www.ureader.com/msg/1435247.aspx”rel=“noreferer”>Here Peter Huang从MS中张贴了这一未经管理的方法:

        [DllImport("gdiplus.dll")]
        private static extern uint GdipEmfToWmfBits (IntPtr _hEmf, uint _bufferSize,
            byte[] _buffer, int _mappingMode, EmfToWmfBitsFlags _flags);
        [DllImport("gdi32.dll")]
        private static extern IntPtr SetMetaFileBitsEx (uint _bufferSize,
            byte[] _buffer);
        [DllImport("gdi32.dll")]
        private static extern IntPtr CopyMetaFile (IntPtr hWmf,
            string filename);
        [DllImport("gdi32.dll")]
        private static extern bool DeleteMetaFile (IntPtr hWmf);
        [DllImport("gdi32.dll")]
        private static extern bool DeleteEnhMetaFile (IntPtr hEmf);
        private void button4_Click(object sender, System.EventArgs e)
        {
            Graphics g= this.CreateGraphics();
            IntPtr hDC = g.GetHdc();
            Metafile mf = new Metafile(hDC,EmfType.EmfOnly);
            g.ReleaseHdc(hDC);
            g.Dispose();
            g=Graphics.FromImage(mf);
            //Pen p = new Pen(Color.White,5);
            g.DrawArc(Pens.Black,0,0,200,200,0,360);
            //g.DrawImage(Bitmap.FromFile(@"c:	emp	est.bmp"),0,0);
            g.Dispose();
            IntPtr _hEmf= mf.GetHenhmetafile();
            uint _bufferSize = GdipEmfToWmfBits(_hEmf, 0, null, MM_ANISOTROPIC,
                EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
            byte[] _buffer = new byte[_bufferSize];
            GdipEmfToWmfBits(_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
                    EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
            IntPtr hmf = SetMetaFileBitsEx(_bufferSize, _buffer);
            CopyMetaFile(hmf, "C:\ConvertedMetafile.wmf");
            DeleteMetaFile(hmf);
            DeleteEnhMetaFile(_hEmf);
        }

希望你:

Answer 2

这里是对这个问题的全面回答,包括我的修改。文森特的答复完全正确。缺少一些定义和一 en。因此,我在此提出“明确”的《工作守则》,希望这对其他人有用。

        [Flags]
        private enum EmfToWmfBitsFlags {
            EmfToWmfBitsFlagsDefault = 0x00000000,
            EmfToWmfBitsFlagsEmbedEmf = 0x00000001,
            EmfToWmfBitsFlagsIncludePlaceable = 0x00000002,
            EmfToWmfBitsFlagsNoXORClip = 0x00000004
        }

        private static int MM_ISOTROPIC = 7;
        private static int MM_ANISOTROPIC = 8;

        [DllImport ("gdiplus.dll")]
        private static extern uint GdipEmfToWmfBits (IntPtr _hEmf, uint _bufferSize,
            byte[] _buffer, int _mappingMode, EmfToWmfBitsFlags _flags);
        [DllImport ("gdi32.dll")]
        private static extern IntPtr SetMetaFileBitsEx (uint _bufferSize,
            byte[] _buffer);
        [DllImport ("gdi32.dll")]
        private static extern IntPtr CopyMetaFile (IntPtr hWmf,
            string filename);
        [DllImport ("gdi32.dll")]
        private static extern bool DeleteMetaFile (IntPtr hWmf);
        [DllImport ("gdi32.dll")]
        private static extern bool DeleteEnhMetaFile (IntPtr hEmf);

        private static MemoryStream MakeMetafileStream (Bitmap image)
        {
            Metafile metafile = null;
            using (Graphics g = Graphics.FromImage (image)) {
                IntPtr hDC = g.GetHdc ();
                metafile = new Metafile (hDC, EmfType.EmfOnly);
                g.ReleaseHdc (hDC);
            }

            using (Graphics g = Graphics.FromImage (metafile)) {
                g.DrawImage (image, 0, 0);
            }
            IntPtr _hEmf = metafile.GetHenhmetafile ();
            uint _bufferSize = GdipEmfToWmfBits (_hEmf, 0, null, MM_ANISOTROPIC,
                EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
            byte[] _buffer = new byte[_bufferSize];
            GdipEmfToWmfBits (_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
                    EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
            IntPtr hmf = SetMetaFileBitsEx (_bufferSize, _buffer);
            string tempfile = Path.GetTempFileName ();
            CopyMetaFile (hmf, tempfile);
            DeleteMetaFile (hmf);
            DeleteEnhMetaFile (_hEmf);

            var stream = new MemoryStream ();
            byte[] data = File.ReadAllBytes (tempfile);
            //File.Delete (tempfile);
            int count = data.Length;
            stream.Write (data, 0, count);
            return stream;
        }

Answer 3

改良版的“jdehaan”版(Akudos btw to his and Vincent)

    [Flags]
    private enum EmfToWmfBitsFlags
    {
        EmfToWmfBitsFlagsDefault = 0x00000000,
        EmfToWmfBitsFlagsEmbedEmf = 0x00000001,
        EmfToWmfBitsFlagsIncludePlaceable = 0x00000002,
        EmfToWmfBitsFlagsNoXORClip = 0x00000004
    }

    private static int MM_ISOTROPIC = 7;
    private static int MM_ANISOTROPIC = 8;

    [DllImport("gdiplus.dll")]
    private static extern uint GdipEmfToWmfBits(IntPtr _hEmf, uint _bufferSize,
        byte[] _buffer, int _mappingMode, EmfToWmfBitsFlags _flags);
    [DllImport("gdi32.dll")]
    private static extern IntPtr SetMetaFileBitsEx(uint _bufferSize,
        byte[] _buffer);
    [DllImport("gdi32.dll")]
    private static extern IntPtr CopyMetaFile(IntPtr hWmf,
        string filename);
    [DllImport("gdi32.dll")]
    private static extern bool DeleteMetaFile(IntPtr hWmf);
    [DllImport("gdi32.dll")]
    private static extern bool DeleteEnhMetaFile(IntPtr hEmf);

    public static MemoryStream MakeMetafileStream(System.Drawing.Bitmap image)
    {
        Metafile metafile = null;
        using (Graphics g = Graphics.FromImage(image))
        {
            IntPtr hDC = g.GetHdc();
            metafile = new Metafile(hDC, EmfType.EmfOnly);
            g.ReleaseHdc(hDC);
        }

        using (Graphics g = Graphics.FromImage(metafile))
        {
            g.DrawImage(image, 0, 0);
        }
        IntPtr _hEmf = metafile.GetHenhmetafile();
        uint _bufferSize = GdipEmfToWmfBits(_hEmf, 0, null, MM_ANISOTROPIC,
            EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
        byte[] _buffer = new byte[_bufferSize];
        GdipEmfToWmfBits(_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
                EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
        DeleteEnhMetaFile(_hEmf);

        var stream = new MemoryStream();
        stream.Write(_buffer, 0, (int)_bufferSize);
        stream.Seek(0, 0);

        return stream;
    }

This one does not leave temp files behind and also avoids copying _bufferSize to a temp file only to then copy it to another buffer. Thanks again guys.

Answer 4

The s a Win32 GDI+ example that work for me (credit to

Bitmap *image;
image = Bitmap::FromFile(L"in.jpg");                // read in the JPG
HDC hdc = GetDC(hwnd);                              // parent window
Metafile *metafile = new Metafile(L"out.wmf", hdc);
Graphics *graphics = new Graphics(metafile);
graphics->DrawImage(image, 0, 0, image->GetWidth(), image->GetHeight());
delete graphics; delete metafile; delete image;
ReleaseDC(hwnd, hdc);

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